Chapter 23. Media Directory. Cardiovascular Disease (CVD) Hypertension: Classified into Three Categories

Transcription

1 Chapter 23 Drugs for Hypertension Slide 37 Slide 41 Media Directory Nifedipine Animation Doxazosin Animation Upper Saddle River, New Jersey All rights reserved. Cardiovascular Disease (CVD) Includes conditions of heart and blood vessels Hypertension is most common form of CVD Most frequent causes of death in U.S Prehypertension Stage 1 Stage 2 Hypertension: Classified into Three Categories Blood Pressure Changes throughout Lifespan Normal B/P at one age; abnormal as we age Heart Brain Kidneys Retina Target Organs Affected by Untreated Hypertension 1

2 Disease Progression Related to Organs Heart failure TIA and/or cerebral vascular accident Renal failure Visual impairment and blindness Cardiac Output Determined by Stroke volume Heart rate Medications that affect cardiac output, stroke volume, heart rate influence blood pressure Peripheral Resistance Blood Volume Friction in arteries as blood flows through vascular system Greater resistance in arteries yields higher blood pressure Medications that affect vascular smooth muscles may lower or raise B/P Autonomic nervous system plays role in controlling peripheral resistance Total amount of blood in vascular system Increased blood volume increases blood pressure Medications that affect blood volume may lower or raise B/P Central and Autonomic Nervous Systems Figure 23.3 Hormonal and nervous factors influencing blood pressure. Regulate blood pressure Vasomotor center Baroreceptors Chemoreceptors 2

3 Emotions Affect Blood Pressure Endocrine System Stress and anger increase Depression and lethargy decrease Regulates blood pressure Natural hormones affect blood pressure daily Epinephrine and norepinephrine injections raise B/P Antidiuretic hormone raises B/P by raising blood volume Assessment of Client s Lifestyle Dietary habits Exercise or activity regimen Use of medication Genetic Factors That May Contribute to Client s Hypertension Risk Race Gender Family history of hypertension Environmental Factors That May Contribute to Client s Hypertension Role Tobacco use, high-fat diets, obesity Excessive sodium intake or alcohol consumption Sedentary lifestyle Factors That Can Help Control Blood Pressure Losing weight Limiting foods high in fat and sodium Limiting use of tobacco and alcohol Beginning an exercise program 3

4 Primary Antihypertensive Agents Diuretics Angiotensin-converting enzyme (ACE) inhibitors Angiotensin II receptor blockers Beta-adrenergic antagonists Calcium channel blockers Secondary Antihypertensive Agents Alpha1-adrenergic antagonist Alpha2-adrenergic agonists Direct-acting vasodilators Role of Nurse Obtain complete health history Obtain vital signs Do physical examination Obtain blood and urine specimens for analysis for Nonpotassium-Sparing Diuretics Orthostatic hypotension Laboratory electrolyte values, especially potassium level, and daily weights Intake and output assessment of edema and signs of fluid overload Client s ability to safely ambulate Photosensitivity Possible need to increase potassium in diet or with supplements for Potassium-Sparing Diuretics Use of salt substitutes and potassium-rich foods Use in pregnant and lactating women History of gout and kidney stones Uric-acid levels Gynecomastia and hirsutism for spironolactone (Aldactone) Points for Thiazide-like Diuretics Laboratory values (CBC, electrolytes, chemistry panel) Blood-glucose and uric-acid levels Possible need to increase potassium in diet or with supplements Pregnancy and lactation, systemic lupus erythematosus, and use of digoxin 4

5 Points for Loop Diuretics Severe potassium loss Hypovolemia Hypotension Hearing loss (these drugs are ototoxic) Glucose and uric-acid levels Points for CCBs (continued) Obtain ECG, heart rate, and B/P prior to therapy During therapy, monitor heart rate and B/P regularly Health history specific for heart dysrhythmias and pregnancy Signs of CHF and reflex tachycardia Points for CCBs (continued) IV administration, special concern Dizziness, headache, flushing are minor side effects Avoid drinking grapefruit juice Points for Renin-Angiotensins Baseline vital signs Hypotension Angioedema Neutropenia or agranulocytosis for Renin-Angiotensins (continued) Hypokalemia Dizziness, light-headedness, headache Tickling, nonproductive cough Pregnancy-risk category D for Adrenergic Antagonists Baseline vital signs, B/P response Hold medication for pulse below 60 and B/P below 90/60 mm/hg ECG, heart rate and rhythm Watch for heart block and rebound hypertension 5

6 for Adrenergic Antagonists (continued) Routine blood-glucose monitoring for diabetics Alpha1, alpha2, and beta-blocker specific effects Pregnancy-risk categories B and C Points for Direct Vasodilators In emergency: monitor V/S, ECG, and pulse oximetry continuously Contraindicated for Hypersensitivity, coronary artery disease Rheumatic mitral-valve disease, cerebrovascular disease Renal insufficiency, systemic lupus erythematosus for Direct Vasodilators (continued) Priapism IV diazoxide (Hyperstat): monitor sodium and water output Minoxidil (Loniten): monitor for orthohypotension] for Direct Vasodilators (continued) Nitroprusside IV Only mix with 5% dextrose in water Drug extremely light sensitive, only stable for 24 hours Can be used for hypertensive emergencies during labor and delivery Diuretics Calcium Channel Blockers Prototype drug: hydrochlorothiazide (HydroDiuril). Mechanism of action: to increase amount of urine produced and excreted Primary use: for mild to moderate hypertension Adverse effects: electrolyte imbalances, especially loss of potassium Prototype drug: nifedipine (Procardia) Mechanism of action: to cause vasodilation, decreasing B/P Primary use: for hypertension and angina Adverse effects: include dizziness, headache, flushing 6

7 Nifedipine Animation Drugs Affecting Renin-Angiotensin System Angiotensin-converting enzyme (ACE) inhibitors Prototype drug: enalapril (Vasotec) Mechanism of action: to decrease blood volume Primary use: for hypertension Adverse effects: persistent cough and hypotension Click here to view an animation on the topic of doxazosin. Back to Directory Drugs Affecting Renin-Angiotensin System Angiotensin-receptor blockers (ARBs) Prototype drug: losartan potassium (Cozaar) Mechanism of action: to block angiotensin receptors in arterial smooth muscle and adrenal glands Primary use: for hypertension Adverse effect: hypotension Adrenergic Antagonists Prototype drug: doxazosin (Cardura) Mechanism of action: to block affects of the sympathetic nervous system leading to vasodilation Primary use: hypertension Adverse effects: orthostatic hypotension, dizziness, nausea, bradycardia, dry mouth Doxazosin Animation Direct Vasodilators Prototype drug: hydralazine (Apresoline) Mechanism of action: to cause vasodilation by direct relaxation of arterial smooth muscle Primary use: for severe hypertension and hypertension crisis Adverse effects: reflex tachycardia, sodium and fluid retention Click here to view an animation on the topic of doxazosin. Back to Directory 7

8 Drugs Assessment Take client s B/P in each arm for baseline Assess client s height and weight Obtain blood and urine samples as ordered by physician Obtain nursing history, including lifestyle, current medications, dietary habits Assess client s and family s knowledge of hypertension and medication regimen Drugs (continued) Nursing Diagnoses Decreased cardiac output related to excessive or prolonged systemic vascular resistance Knowledge deficit regarding condition, therapeutic regimen, and potential side effects of medications Ineffective therapeutic-regimen management related to complexity of therapy and cost of medications Risk for sexual dysfunction related to side effects of medications Drugs (continued) Planning Goals Exhibit a reduction in systolic/diastolic blood pressure Client is able to explain hypertension and needed medications Client is able to verbalize ability to follow prescribed therapy Drugs (continued) Implementation Encourage compliance Provide education regarding medication regimen Drugs (continued) Evaluation Ideal outcome criteria Lowered B/P with limited side effects Client able to verbalize importance of taking prescribed medications Diuretics Table 23.4 Diuretics 8

9 Calcium Channel Blockers ACE Inhibitors and Angiotensin II Receptor Blockers Table 23.5 Calcium Channel Blockers Table 23.6 ACE Inhibitors and Angiotensin II Receptor Blockers Adrenergic Antagonists Adrenergic Antagonists Table 23.7 Adrenergic Antagonists Table 23.7b Adrenergic Antagonists Direct-acting Vasodilators Table 23.8 Direct-acting Vasodilators 9